1. Field of the Invention
This invention is related to coaxial electrical connectors. More particularly, this connector is related to right angle coaxial connectors, either plugs or sockets. Furthermore this connector is a snap lock connector in which the two connectors are locked together when mated and cannot be disengaged or unmated by application of a simple tensile force to one of the mated connectors.
2. Description of the Prior Art
Coaxial or RF plug and jack electrical connectors typically include means for connecting center conductors in separate coaxial cables and for connecting the outer shield or braid in the two cables. In some cases, the center conductor in one of the cables is connected directly to a socket terminal in the other coaxial connector, but often a pin is attached or crimped to the center conductor in the cable. The center contact and the braid contact in each connector or terminal are typically separated by a cylindrical dielectric surrounding the center contact. The outer contact is typically attached to the braid or shield of a coaxial cable by crimping a ferrule to the braid after the end of the cable has been prepared or stripped.
Once plug and jack coaxial connectors have been attached to sections of a coaxial cable, a number of conventional means have been employed to mate the plug connector to the jack connector. One connector may employ an outer ring with internal threads which can then be screwed to the mating connector with external mating threads. BNC style coaxial connectors employ a laterally facing pin or post on one connector that is captured within a slot on the mating connector. However, both of these coaxial connector configurations require that mating connectors must be mounted by rotating one connector relative to its mating connector. This approach may be satisfactory for many traditional applications, such as field assembly of two coaxial cables, for example connecting two cables in a commercial or residential building. However, when the coaxial cables are used in a larger component or subassembly, such as a harness in an automobile or motor vehicle, that is assembled in a large scale production environment, screwing the two coaxial connectors together is undesirable.
One alternative to coaxial connectors that are mated by screwing one connector to another, is to employ a snap-on or quick connect, quick disconnect configuration in which one coaxial connector is simply pushed into mating engagement with the other coaxial connector without mutual rotation. These prior art snap-on connectors typically include a plurality of screw machined or die cast spring fingers in a cylindrical configuration. Adjacent spring fingers are separated by slots and include mating ridges adjacent their free ends. The individual spring fingers can be radially when pushed onto a mating connector having a diameter that differs from the normal neutral position of the spring fingers. The spring fingers can be deflected inwardly or outwardly, depending on whether they are inserted into a bore in cylindrical sleeve or over the exterior of a cylindrical barrel. When the quick connect, quick disconnect, snap-on connectors are fully mated, the spring fingers are received within a groove or recess on the mating connector, so that the spring fingers return to their neutral position. Examples of coaxial connectors of this general type are shown in U.S. Pat. Nos. 4,017,139; 4,412,717; 5,842,872; and 6,036,540. Although conventional coaxial connectors of this type do not require rotational movement for mating, the disconnect force is typically approximately the same as the connection or mating force. Thus quick connect, quick disconnect coaxial connectors cannot be locked when mated, so that a significantly greater force is required to unmate or disconnect the coaxial connectors than was required to mate them. The fact that these prior art connectors cannot be locked together can cause problems when they are used in automotive applications or in harness assemblies for use in similar applications, because the connectors can be inadvertently dislodged during assembly or pulled apart when a force is applied to one of the coaxial cables, possibly as part of a later assembly operation. Vibration due to movement of the automobile or similar apparatus can also cause disengagement of the mated coaxial connectors.
The use of a locking molded collar assembly formed by mating hermaphroditic housings is shown in commonly assigned U.S. patent application Ser. No. 09/738,675 entitled Snap On Plug Coaxial Connector. That patent shows an in-line coaxial connector assembly instead of a right angle coaxial connector. An example of a right angle coaxial connector with spring finger for engaging a mating connector is shown in U.S. Pat. No. 6,036,540. However, that connector does not provide a means for locking the two connectors together.
Some applications for coaxial connectors require the use of a right angle connector. Space limitations can dictate the use of a right angle connector instead of a more common in line coaxial assembly. Automotive assemblies are one example of an application in which other limitations can require the use of the more complicated right angle connector. A right angle coaxial connector, either a plug or socket, is physically more difficult to manufacture and to terminate. The instant invention provides not only a right angle coaxial connector, but also provides one in which two coaxial connectors can be locked together so that they cannot be disengaged or unmated by simply pulling on one of the connectors. Additional force or manipulation is required to disconnect the connectors. This requirement also complicates the manufacture of these connectors, and the instant invention provides a relatively simple manufacturing approach to a connector assembly including both a shell and a shiftable collar. The shell has two parts. In the preferred embodiment a rear shell is diecast and a front shell is screw machined. Since the front shell contains flexible snap lock fingers, damage to the fingers can be minimized by screw machining the front shell.
This invention, which achieves these and other objectives, comprises a right angle coaxial electrical connector assembly that includes a center contact; a dielectric surrounding the center contact; a shell subassembly surrounding the center contact and the dielectric, and a collar subassembly. The shell subassembly is positioned between the dielectric and the collar subassembly. The collar subassembly is in turn spring loaded and shiftable relative to the shell subassembly;
The shell subassembly includes a front shell attached to a rear shell. The rear shell has a first passage extending at a right angle relative to a second intersecting passage. The center contact and the dielectric are positioned within the first passage. The second passage is dimensioned to receive at least a portion of a stripped end of a coaxial cable to which the connector is to be attached.
The collar subassembly is generally coaxial relative to the first passage and the front shell includes at least one radially flexible spring finger extending beyond the rear shell. This collar subassembly is shiftable between a first or neutral position and a second position relative to the shell subassembly. The collar subassembly engages the spring finger in the neutral position to prevent radially outward deflection of the spring finger. The spring finger is spaced from the collar subassembly in the second position so that the spring finger can shift radially outward when the collar subassembly is in the second position. This connector can thus be locked to a mating connector and cannot be unmated until the collar is shifted longitudinally relative to the shell.